A Manhattan mom — whose estranged husband once falsely accused her of molesting their kids — is now asking a judge to give her decision-making power over their 16-year-old son after her ex claimed she was trying to “make [him] gay.”

Danica Cordell-Reeh’s attorney, Thomas Shanahan, detailed the latest twisted allegations last week to Justice Lori Sattler, who set a September hearing over the claims. Former Goldman Sachs honcho Henry Owsley III recently informed administrators at his 16-year-old son’s new California boarding school that his former spouse “was trying to make her son gay in order to get back at him,” Shanahan told Sattler.

Owsley, 59, also accused his wife of forcing their son and his twin sister to participate in seances to summon their dead grandmother, Shanahan said in court. The former high-school sweethearts, who both live on the Upper West Side, currently share custody of the twins.

After the hearing, the lawyer told The Post that Cordell-Reeh, 56, was “in tears” over the false claims.

“She needs to have her day in court,” he said.

An independent attorney for the teen told Sattler the boy was “trying to find himself.”

The former couple is back before a matrimonial judge 10 years after a state official said Owsley’s claim that his wife had sexually abused their children — originally reported by their nanny — was bogus. But Owsley hasn’t dropped the sex-abuse allegations, repeating them to his son’s school with the other new claims, Shanahan told the judge.

During their first court battle, in 2002, Owsley temporarily got sole custody of the twins after telling the court that a recently fired nanny said his wife was starving her children and making them perform lewd sex acts on her.

To clear her name, Cordell-Reeh’s attorney at the time, Bernard Clair, hired a private investigator who discovered that the nanny had made similar accusations against another employer and her own sibling.

Outside court, Owsley would only say, “I’m trying to be a private person. My children are clearly private people. I’m very sensitive about it.”

The judge put on hold a lawsuit Owsley brought against his ex last month saying she had billed him $263,000 for no-show nannies. Owsley claims his twins tattled that their nannies were absent during times Cordell-Reeh had billed him to pay for their services.

Owsley, currently the head of the Gordian Group investment bank, is seeking $2.5 million in damages from his real-estate-broker ex in the stayed suit.

The judge urged the two sides to get along for the sake of their children.